Heirsh

Well one thing that really attracts me to Colins stuff is that you dont need the turbo tail. We can talk about the complexity of the turbo system vs Colins, or the efficiency (early turbos arent known for the fuel efficiency and Colins is an unknown at this point), or the lag. 400+hp N/A in the narrow body with a regular tail though...

Not that I have anything against a wide turbo tailed car, but I personally prefer narrow with no tail.

As for upgrading a 3.6 turbo I'm sure you are right.

Eggplant Cab

Heirsh
That's why I suggested the Turbo II. They fixed most of the niggles in the Turbo. I was looking at one way back in 93 but decided on the cab instead. There are also emissions issues where emissions are enforced vs the UK.Plus Colin is in the UK, and the OP is in IN.
Being aircooled, I'd prefer having a cooler engine than a cooler looking car (which is very subjective)
The Turbo II also has an uprated LSD, brakes and suspension as well as wider track.

AVoyvoda

The Turbo lags, and as importantly won't give you the same low-down grunt as the na. It isn't easy driving within a narrow power band on the street. Therefore, given two engines of similar power, I'd choose the na.
The Turbo is 4wd (which some people don't like) and heavier (another negative).
As to the LSD, brakes and suspension, just fit them. It would be expensive, of course, but the originator of the thead did mention "assuming money no object".

Red rooster

These days 150bhp/litre is easily acheived by production water cooled turbo motors while retaining a wide power band.
Even though the air cooled motor has thermal issues I dont see the point in building a fragile N/A 4.0 litre semi-race motor to acheive a peaky 400-450 bhp !
As an alternative a centrifugal blower has turbo like compressor efficiency and runs with N/A head temperatures.
Decisions,decisions !!

Geoff

zimpwh

Does anyone produce a twin screw positive displacement supercharger setup for the 964 engine other than TPC? Is Superchargers of Knoxville still in business? .

AVoyvoda

"These days 150bhp/litre is easily acheived... with water cooled turbo motors". Sorry RR, thought we were talking about 964s not what's available today. In terms of "building a fragile N/A 4.0" not sure I agree. Bar the case itself, everything is brand-new and designed for the purpose (crank, pistons, heads, valves, rods etc). If Ferrari can generate a reliable 480hp from a 4.3 litre na street engine (the F430), then why not 400 hp from a 4 litre street engine (more from a race engine)?
I think that anybody contemplating this, must first be satisfied that:
He/she wants an air cooled 964/993 not a modern alternative, and
No fixed wing in the back.
On this basis (bar a water-to-air intercooler) there is no alternative to what Colin is offering. Of course, if you are looking for the "ultimate" in terms of power, technology has moved on and brand new cars (from Porche and others) will produce more power.
As to value for money, that's a personal choice.

ChaseN

No, all the 965 series turbos are RWD

rideshootanddrink

Lag??? What lag??? Give me a break...that lag issue is way overblown. I have both 930 and 964. Those cars have very different characters indeed, but with updated exhaust and better turbo lag is almost absent down low. I'd think down low grunt is about the same (on my cars), but after 4k really there is no contest, turbo is gone. If that's your cup of tea, then go for it. With that being said, I think it's just silly to have 930 on the street with the amount of power this car has. Light weight and HP is a very addictive combination.

911addict

Yes, I have a turbo2 3.3 (which can be modified to 400bhp if one is that way inclined). I had NA 3.2's for previous 6 years and confirm my turbo does not have a lag issue (especially with my fitted 100cell cat).

As to adding a turbo to a NA 964, I guess you would have to look at upgrade of brakes and handling, whereas the 965 is a pretty well put together car anyway.

I am a street driver, so can't comment on the track.

If money is no object then a NA car is always going to be MORE perfect :-)

BTW, Colin, I have been in JBL930's Ninemeister 500bhp 930 and turbo lag definitely does not apply.....

NineMeister

Ah, now with JBL's turbo you are really looking at a completely different animal, we broke the mould with that one when we dumped the KKK and pretty much engineered the perfect hybrid ballrace turbo which completely redefines the torque curve - from memory it has more than 450Nm from 3000 to 6500. However, even with the area under the curve that this one has I personally would still prefer a 400hp n/a engine for either road or track unless straight line speed was the only consideration.

The simple reason is that even if you run a very sophisticated engine management system on a turbo engine you just do not get the same throttle response and sensitivity that the n/a engine delivers - when that turbo is boosting at 1.0 bar it does not matter if the throttle is at 90% or 100%, you get the same power. If you imagine that you are exiting a bend close to the limit of grip, you need to have control within a 10-20hp range else you are fighting oversteer, so even if you have a really well set up narrow bodied chassis like TonyT's the sheer driveability of the 400bhp n/a would allows you to keep everything in balance, whereas a turbo with similar would never have the finess to keep the car on the edge of grip.

And before we get into a big debate over this we need to look no further than the stock 996GT2 and GT3 as a perfect example, the GT2 is more refined and lag free than any 930/965/993 turbo could ever be yet the less powerful GT3 is a faster & safer car around the track. You always end up feeling like you have fought a tiger when you drive a turbo fast, yet with a powerful n/a you feel like you have been out for a dance.....

agentpennypacker

I would lighten that thing up and go with the best 3.8 kit you can get. No affiliation, but I've heard great things on 9m and the design of their heads...

911addict

Ninemeister said "You always end up feeling like you have fought a tiger when you drive a turbo fast".

I know that feeling!

108.5dba-static

Money no objective...........................!!!!

GT1 or RUF CTR, if you can find either or wait until the 997 RSR comes out - if you cant wait then a 997 Turbo or 997 GT2 (with life insurance). Yes I know its watercooled, but having just sat in the 997 Turbo yesterday (no test drives for a scruffy bloke in a Beemer), you can almost see that Porsche have really moved the benchmark.

If you intend to modify then stick to twin Turbos over superchargers with a nice big intercooler - oh yes we are back to the RUF CTR.

garrett376

...that is such a great description! Very well put!

Christer

Actually, the 964 version is RCT or at least it was the last time I looked. Not wanting to be pedantic of course!